The present invention relates generally to vinyl siding and, more particularly, to vinyl siding having at least one relatively straight, planar portion.
Vinyl siding may be produced by extruding at least one vinyl composition. For example, vinyl siding can be made by co-extruding a vinyl substrate and a vinyl capstock. The extruded vinyl is passed through a calibrator, e.g., a die, to obtain a final net shape. However, as the vinyl cools after passing through the calibrator, it has an inherent tendency to oil can. As is well known in the art, oil canning refers to the inherent tendency of a sheet of vinyl to curve in either a concave or convex direction as it cools.
As a result of the oil canning effect, it has been believed by those skilled in the art that it is not possible to produce vinyl siding having at least one relatively straight, planar portion. Thus, the designs of vinyl siding have been limited. Vinyl siding commonly has at least one horizontal row. Each row of the siding is subject to the oil canning effect. Consequently, in order to limit the oil canning effect, it has been tried to limit the width of each row and the height of each seam connecting adjacent rows. Moreover, it is common to produce the vinyl siding such that each row already has a significant amount of curvature as it exits the calibrator so as to minimize the oil canning effect. These design considerations have limited and/or diminished the appearance of the vinyl siding. Therefore, a need exists for a vinyl siding panel that has at least one relatively straight, planar portion despite the inherent tendency of vinyl siding to oil can.
One embodiment of the present invention is a vinyl siding panel comprising a planar portion extending the longitudinal length of the vinyl siding panel. The planar portion comprises a first edge and a second edge. The width from the first edge to the second edge is at least about 4.0 inches. In addition, the planar portion has a surface variance of less than about 0.05 inches relative to an imaginary straight line connecting the first edge and the second edge.
A second embodiment of the present invention is a vinyl siding panel comprising a planar portion extending the longitudinal length of the vinyl siding panel. The planar portion comprises a first edge and a second edge, wherein the width from the first edge to the second edge is at least about 4.0 inches. In addition, the radius curvature between the first edge and the second edge is at least about 85 inches.
A third embodiment of the present invention is a method of producing a vinyl siding panel having a substantially straight, planar portion. The method comprises extruding at least one vinyl composition and passing the vinyl composition(s) through a calibrator defining a passageway corresponding to the substantially straight, planar portion. The passageway has a first edge and a second edge. The width from the first edge to the second edge is at least about 4.0 inches, and the surface variance is less than about 0.05 inches relative to an imaginary straight line connecting the first edge and the second edge.
A fourth embodiment of the present invention is also a method of producing a vinyl siding panel having a substantially straight, planar portion. In this embodiment, the method comprises extruding at least one vinyl composition. The vinyl is then passed through a calibrator defining a passageway corresponding to the substantially straight, planar portion. The passageway has a first edge and a second edge. The width is at least about 4.0 inches from the first edge to the second edge, and the radius curvature between the first edge and the second edge is at least about 85 inches.
In addition to the novel features and advantages mentioned above, other objects and advantages of the present invention will be readily apparent from the following descriptions of the drawings and exemplary embodiments.